1. Field of the Invention
The present invention relates to a system and method for controlling an exhaust brake of a vehicle. More particularly, the present invention relates to a system and method for controlling an exhaust brake of a vehicle that improves a low and medium speed of an engine and prevents damage to vehicle components by maintaining back pressure of the exhaust brake to be constant at any rotation speed of the engine.
2. Description of Related Art
Generally, commercial vehicles such as trucks have an exhaust brake supporting a main brake such as a footbrake. The exhaust brake degrades the engine operation by forcibly suppressing exhaust gas which is released into the atmosphere after burning inside an exhaust pipe communicating with an exhaust manifold.
The conventional exhaust brake for vehicles has a butterfly valve equipped at an exhaust system of engine for controlling an exhaust gas flow. If the butterfly valve is closed, then back pressure is generated by shutting off the exhaust pipe and the engine speed is reduced by rotational resistance of the crank shaft, and as a result the vehicle slows down.
In this case, a hole might be formed in the butterfly valve so as to satisfy permissible back pressure, and the performance of the exhaust brake can be fine-tuned by adjusting the size of the hole.
However, the conventional exhaust brake has a problem of performance degradation at low and medium engine speeds such as the main speed of an engine by fixing the valve opening of the exhaust brake so as to maintain the back pressure below the permissible back pressure at a maximum rotation speed of the engine.
The conventional exhaust brake has a further problem that components of the engine can be damaged by excessive back pressure caused by an excessively high engine speed, because the opening of the butterfly valve is constantly maintained even when the engine speed is excessively high.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.